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Analysis of the ISOPHOT FIR maps of M51 and M101.
Lemke, D.; Telesco, C. M.; Kinkel, U. +6 more
The far-IR ISOPHOT maps of the spiral galaxies M51 and M101 at 60, 100, and at 175µm are analysed. For all areas in these galaxies the spectral energy distributions can be fitted with a single-temperature emission curve. Colours and dust temperatures were estimated for interesting sub-fields. The temperatures vary between 33K for HII regions…
A study on the nature of the peculiar supergiant HD 101584.
Waters, L. B. F. M.; Lamers, H. J. G. L. M.; Trams, N. R. +3 more
We present a study of low- and high-resolution ultraviolet, high-resolution optical CAT/CES spectra and ultraviolet, optical and infrared photometry of the peculiar supergiant HD 101584. From the photometry we learn that the ultraviolet and optical energy distribution cannot be fitted in a consistent way and we need a model in which the UV and opt…
Coronal radio sounding with Ulysses: solar wind electron density near 0.1AU during the 1995 conjunction.
Bird, M. K.; Asmar, S. W.; Paetzold, M. +2 more
Dual-frequency ranging measurements were recorded for a three-week interval during the 1995 solar conjunction of the Ulysses spacecraft. The unusual occultation geometry resulting from the high inclination Ulysses orbit enabled coronal radio sounding from the solar South Pole to the heliographic equator at solar ray path offsets near 0.1AU. The el…
ISO observations of hot dust in the nucleus of the S0 galaxy NGC 3998.
Rupen, M. P.; Fich, M.; Knapp, G. R. +2 more
ISOCAM maps of the Seyfert 1 S0 galaxy NGC 3998 between 4.5µm and 15µm detect both extended emission from the bulge stars and strong point source emission from the nucleus. The inner regions of NGC 3998 appear to contain a few thousand solar masses of warm (~200K) dust, probably associated with the AGN.
A damped Lyα candidate at z~0.1 towards Q0439-433.
Petitjean, P.; Smette, A.; Theodore, B. +1 more
We report on the detection of a Z_gal_=0.101 galaxy projected on the sky at 4.2arcsec (or 5.2h^-1^_100_kpc for q_0_=0.5) from the quasar Q 0439-433 (z_em_=0.594). The HST spectrum of the quasar shows strong Mg II, Fe II, Si II, Al II and C IV absorption lines at the same redshift as the galaxy. The equivalent width ratios of the low ionization lin…
Langmuir waves associated with discontinuities in the solar wind: a statistical study.
Tsurutani, B. T.; Kellogg, P. J.; MacDowall, R. J. +2 more
We have reported previously that short bursts of Langmuir waves are frequently observed in the solar wind in isolated local depressions in the magnetic field magnitude, which are called "magnetic holes". The magnetic depression regions are often bounded by directional discontinuities (DDs). To study the relation between the waves and the discontin…
Components of the ultraviolet continuum in active galactic nuclei.
Paltani, S.; Walter, R.
The ultraviolet spectral slope of individual active galactic nuclei (AGN), measured using IUE observations, varies considerably with time. Neither accretion disks nor optically thin emission models can explain these variations. We propose here a method based on the variability properties of these objects to disentangle various components of consta…
ULYSSES COSPIN/LET: latitudinal gradients of anomalous cosmic ray O, N and Ne.
Klecker, B.; Bothmer, V.; Sanderson, T. R. +4 more
A key goal of the Ulysses mission is the measurement of the latitudinal gradient of the Anomalous Cosmic Ray (ACR) component. Earlier studies using data from the COSPIN/LET experiment on board Ulysses together with in-ecliptic data from the HILT instrument on SAMPEX have shown a small (~2% per degree) positive latitudinal gradient for anomalous ox…
Is 2RE J0357+283 the most coronally active star in the Galaxy?
Jeffries, R. D.; Burleigh, M. R.; Robb, R. M.
The late-type stellar counterpart to the EUV source 2RE J0357+283 is found to be an ultra-fast rotating K2V star, with a rotation period of 8.76 hrs and vsini of 141+/-5km/s. If this were the only source of the EUV emission, then it would be the most coronally active star known, by an order of magnitude, and requires a reappraisal of current ideas…
First results from a photometric infrared survey for Vega-like disks around nearby main-sequence stars.
Waters, L. B. F. M.; Kessler, M. F.; Siebenmorgen, R. +12 more
We have undertaken a survey for Vega-like disks around nearby main-sequence stars by making photometric measurements with ISOPHOT at four wavelengths between 25 and 180µm. Our goal is to establish how common Vega-like disks are, and how their presence depends on the fundamental properties of main-sequence stars (mass, age, rotation etc.). He…